2 monitors

I have my standard monitor pluged into my computer and it works great,
But i also have another which i would like to use aswell.
I have 2 graphics card (geforce 2 and voodoo 3).
If i plug my spare graphics card into my computer and my other omnitor into that will windows xp pro detect it and thats that,
or do i have to do somethiung else ?

If i do put them both on and i want to play a game does it stretch across the 2 screens because i don't wnat that !